China has formally charged Ling Jihua, a former aide to ex-president Hu Jintao, with corruption.

Mr Ling had taken bribes, stolen state secrets and abused his power, state prosecutors said.

He was in effect chief-of-staff to President Hu, but was demoted in a surprise move in 2012.

China is running a high-profile campaign against corruption, and says it punished nearly 300,000 officials in 2015 alone.

Mr Ling had held a senior position in President Hu's government as head of the Central Committee's General Office.

There was speculation that his demotion may have been the result of political manoeuvring ahead of a leadership change - but there were also reports that his son's involvement in a Ferrari crash may have been to blame.

The authorities announced an investigation into him in late 2014, and he was expelled from the Communist Party and arrested in July 2015.

President Xi Jinping has made a campaign against corruption a centrepiece of his governing agenda.

Many high-profile political figures have been jailed after being caught in the net.

However, some observers see the anti-corruption campaign as a way for the Party to rein in officials seen as becoming too influential, or as a means of pursuing personal vendettas.